Postal sorting apparatus



9 Sheets-Sheet l May 4, 1954 J. PIGGoTT ET Al.

POSTAL SORTING APPARATUS Filed Aug. 9, 1951 May 4, 1954` J. PlGGoT'r E-r AL 2,677,473

POSTAL SORTING APPARATUS Filed Aug. 9, 1951 Q'Sheets-Sheet 2 May 4, 1954 J. PIGGOTT ETAL POSTAL SORTING APPARATUS Filed Aug. 9, 1951 9 Sheets-Sheet 3 INNUU!" May 4, 1954 J. PIGGoT-r ETAL POSTAL SORTING APPARATUS 9 Sheets-Sheet-4 Filed Aug. 9, 1951 May 4, 1954 J, PIGGOTT ET AL 2,677,473

POSTAL SORTING APPARATUS Filed Aug. 9, 1951 9 Sheets-Sheet 5 V Pl 2l Q2 I 17a |7a.\ l, I8

May 4, 1954 J PIGGoT-r ETAL 2,677,473

POSTAL SORTING APPARATUS Filed Aug. 9, 1951 9 Sheets-Sheet 6 F/G. /0 F76.

May 4, 1954 J. PIGGOTT ET AL 2,677,473

POSTAL SORTING APPARATUS Filed Aug. 9, 1951 9 Sheets-Sheet 7 May 4, 1954 J. PIGGoT-r E-r AL 2,677,473

POSTAL SORTING APPARATUS Filed Aug. 9, 1951 9 Sheets-Sheet 9 Patented May 4, 1954 UNITED STATES iATENT OFFICE POSTAL SRTING APPARA'IUSy John Piggott, Northwood, Arthur Frederick Whillock, Chesiiam, and Paul Ernest Marriott, Kenley, England, assignors to Hall Telephone Accessories Limited, London, England Application August 9, 1951, Serial No. 241,132

30 Claims. l

so disposed in relation to each other that a letter released from one trap will drop into the trap below it and be retained therein until actuation of the release means associated with that trap.

The apparatus in a particular form may comprise key operated manually controlled electromagnetic devices for actuating the release means, the manually operated keys serving to control the to a viewing position in which each letter is is circuits of the electromagnetic devices and code viewed by the operator of the apparatus who storage means which determine the instant of then depresses a key or keys coded in accordance subsequent discharge of the letters from the apwith the destination of the letter. Key actuation paratus onto a belt conveyor. is accompanied by release'of the letter from the Apparatus according to the invention may also viewing position to a Waiting position from which 15 comprise means for conveying the letters ater it is subsequently passed to a belt conveyor and release from the iinal trap to one or another oi later ejected into a container corresponding with a plurality of horizontal conveyors disposed verits destination. The ejection of the letter may tioally one above another, each of the said conbe eiiected by means actuated in response to veyors having associated therewith a container or electrical frequencies e. g. audio frequencies of go plurality of containers identified with letter desdistinctive tone recorded on a tape which moves in tinations. synchronism with the belt conveyor the tone In order that the invention may be clearly being recorded at the instant of placing the letter understood and readily carried into effect, one on the belt conveyor. practical form of apparatus constructed in acln order that large quantities of letters may cordance therewith will hereinafter be described be dealt with by a single equipment, several opby Way of example and with reference to the erators positions may be provided and the caaccompanying drawings in which: pacity of the equipment to deal with a large Fig. l is a side elevational View of apparatus number oi destinations may be increased by proconstituting an operators position of a letter viding additional belt conveyors disposed vertisorting machine arranged and adapted to operate cally one above another. Such additional belt in the manner above set forthg' conveyors may be provided with synchronously Fig. 2 is a iront elevational View of the appadriven individual tape records, destination conratus looking in the direction of the arrow Il tainers and devices for ejecting the letters into (Fig. l) and indicating diagrammatically a form the containers. It will be appreciated that conof pneumatic separator means for feeding letters siderable practical problems are involved in the one by one to the apparatus; design or suitable apparatus for transporting light Fig. 3 is a diagrammatic plan view of the appaarticles such as letters from point to point in `ratus and associated means for feeding letters equipment of the kind referred to. It is essento and conveying letters from the apparatus; tial for reliability in operation that the feeding 40 Fig. 4 is a rear elevational view looking in the of the letters through the successive stages from direction of the arrow IV (Fig. l) separation from a stack to the placing of the Fig. 5 is a side elevation, drawn to a larger scale, letters on one or another of the belt conveyors of the letter presentation unit of the apparatus; shall be under accurate control and all move- Fig. 6 iS a Dart broke-Tl away I'OYlt evln ments shall be positively timed within fairly thereof looking in the direction of the arrow Vl close limits. The present invention seeks to (Fig. 5); meet these requirements. Figs. 7 9 are cross sectional views taken on According to the present invention, apparatus lines VLC-VII, VlII--VIII and IX-IX respecfor distributing articles such as postal letters, tively of Fig. 5; postcards or packets in accordance with their Figs. l0 and 1l are detail views, drawn to a destinations or other characteristics comprises larger scale, of the operating and locking means traps or the equivalent, spaced one above another associated with the releasable floors of letter and each provided with releasable means for traps embodied in the apparatus; retaining a letter passed into the trap until the Fig. 12 is a fragmentary view of part or" the releasable means are actuated, the traps being letter distributing unit of the apparatus drawn 3 to a larger scale and showing the letter diverting and guiding means in detail;

Fig. 13 is a fragmentary partly broken away view looking in the direction of the arrow XIII (Fig. 12);

Fig. 14 is a fragmentary detail View drawn to a larger scale to show an alternative form of electro-magnetically operated floor or gate for the traps of the letter presentation unit of the apparatus;

Fig. l is an elevational View of the construe-- tion shown in Figure 4 looking in the direction of the arrow XV (Fig. 14)

Fig. 16 is a detail view of the means for coupling the floor or gate flaps to the electromagnetic operating means shown in Figs. 14 and 15.

Referring more particularly tov Figs. 1 3 of the drawings, it will be seen that the apparatus ccmprises a letter presentation unit P, letter distributing unit D and operating keyboard Ii." conveniently disposed for manipulation by a seated operator O, and has associated therewith a loading track conveyor BI for passing letters from the distributor unit D to a main conveyor Ci; letter gun track conveyors BZ-BS for passing letters from the distributor unit D to main conveyors C-CS through the medium of letter guns G; and a pneumatic separator S for separating letters from a stack of letters SL and feeding the letters one by one to the letter presentation unit P.

The distributor unit D is built into a metallic framework comprising two vertical channel members I of appropriate section joined by upper and lower L-seotion horizontal members 3 respectively, the outwardly projecting horizontal anges of the lower members 3 forming feet upon which the frameworkis supported at ground or floor level.

The letter presentation unit P is built between a pair of elongated side plates E, 5a rigidly connected together and held in appropriately spaced relation by tubular spacer members and co-operating screwthreaded S. rEhe upper and lower ends of the side plates 5, 5d are connected to the outer ends of angle section rails S secured to and projectingl forwards from the vertical frame members I and thus form part of a rigid structural framework which may conveniently be in the order of ten feet high and have the upright members thereof spaced at about twelve inches apart.

As shown in detail Figs. 5-9, the lower vertical end parts of the side plates E, of the letterpresentation unit D are forwardly offset from the upper vertical end parts thereof and the two vertical parts of each plate joined by an inclined intermediate part. Rear wall members S, Il and Ia and front panel members ii, i2 and Ill extend between and are nxed to the side plates 5a so as to form therewith a chute of rectangular cross section throughout its length and divided by deflectible loors or gates as hereinafter described into three letter traps ifi, i5, I6 disposed one above the other in uppermost, middle and lowermost positions hereinafter referred to as the feeding, viewing and waiting positions respectively. As shown, the width of the viewing position trap I5 is less than that of the other traps. The rear wall members 3, I3 and lea comprise sheets of any suitable material, e. g. mild steel sheet, having the inner surface thereof smooth faced. The middle front panel member I2 will be made of plate glass or other transparent sheet material suitable for use as a viewing window, while the uppermost and 4 lowermost front panel members may be made of a suitable opaque or translucent sheet material or may be made of transparent sheet material e. g. glass or a transparent solid plastic for reasons hereinafter described.

All of the front panel members may be fixed in position between the side plates 5, 5a in a readily removable manner, and the member I2 forming the viewing window may be secured to the plates by hinged brackets so as to hinge about itsA lower horizontal edge,

The arrangement of the chute and letter traps is such that the feeding position trap Irl is substantially vertical, the viewing position trap I5 and viewing window thereof forwardly and downwardly inclined, and the waiting position trap I6 substantially vertical; the viewing position I5 being disposed at approximately the level of the head of the operator O when the operator is seated at the keyboard K which is supported from the framework of the apparatus for convenient manipulation by the seated operator.

As shown in Fig. 7, the feeding position trap I4 is open at one side and the corresponding side edges of the front panel II and rear wall 9 thereof outwardly curved or flared to form a mouth and passage for letters L fed to the trap, one by one from the stack SL and arranged so that the address side of each letter is correctly oriented and faces the operator. The speciication of co-pending U. S. application Ser. No. 241,131 describes an appropriate form of letter separating and feeding device for the purpose, and the pneumatic separator S, stack SL and snatch rollers R arranged for passing the letters into the trap, as shown diagrammatically in Fig. 3, form part of such a device.

A letter L so received by the trap ILl from 'the separator device will drop edgewise on to a horizontal deilectible iioor I'l which extends across the chute below the level of the bottom edge It. of the mouth of the trap and serves releasably to hold the letter in the feeding position. ri'he raised bottom edge I2 of the trap mouth forms a stop or step which engages the rear end edge of any letter which may attempt to bounce back out of the trap into which it is projected by the fast moving snatch rollers R.

The trap floor IT comprises a horizontal plate held at the lower ends of inclined arms la xed to a transverse rod I9 which is pivotally mounted in bearings provided in the side plates 5, 5d and disposed in front of the trap lli. One end of the pivotal rod 19 extends outw'rds from the supporting side plate 5 to receive a twist spring 29 which is anchored at one end thereof to the side plate and has its further end engaged with a short crank arm- 2! keyed to the pivotal rod I9. The twist spring 20 thus acts normally to hold the door Il in the trap-closing 'position as shown in Figs. 6 and '7. llhearmature 22 of a solenoid 23, which is mounted on the side plate 5 beneath the projecting end of the rod I9 and twist spring 20, is coupled to the spring-loaded crank; arm 2l so that on energisation of the solenoid the armature thereof is drawn downwards to rock the rod in clockwise direction (as viewed in Fig. 5) and thus move the trap floor il for-- wardly and downwardly from the bottom of the trap and into the space between the front panel members I I and I2 to permit the letter l'.- resting thereon to drop into the-viewing position trap I5.

A letter dropped into the viewing position from the feeding position will rest edgewise upon the deiiectible floor of the trap I5 consisting of a row of light metal bars 24 supported from arms 2da, the bars and arms being formed as integral parts of bent metal strips fixed to a transverse rod which is pivotally mounted in bearings provided in the side plates 5, 5a and disposed behind the trap l5, the bars 24 and arms Ella passing through clearance slots provided in the rear wall il).

In order to prevent the dropped letter from bouncing from the floor of the trap i5 and also to maintain the addressed face of the letter as close as possible to the inner face of the viewing window, curved light wire lingers 2S are arranged to engage the rear faces of the falling letters so as to guide and hold each letter against the viewing window. The curved ngers 2S are mounted upon another transverse rod 2l which is pivotally mounted in the side plates 5, ta behind the trap i5 and the lower ends of the wire fingers lie in clearance recesses formed in the free ends of the floor bars and pass therewith through the clearance slots in the rear wall iii.

rEhe ends of the rods 25 and 27 project outwards from the side plate 5 to receive operating crank arms 2S, 29 and twist springs 30, 3| which re-act between the crank arms and side plates yieldingly to hold the floor forming bars 24 and wire fingers 25 in the letter-holding position shown in Figs. 5 and 6.

The rods 25 and 2'! are linked together for concerted movement by means hereinafter described and are operated by a solenoid 32 mounted upon the side plate 5 immediately above the projecting ends of the rods 25, 2 and having its armature 33 coupled to the crank arm 25.9, so that upon energisation of the solenoid 32 the pivotal bars 25, 2l are rocked in anticlockwise direction (as viewed in Fig. 5) and the floor bars 2d and s ring wire lingers 26 withdrawn downwardly and rearwardly from operative position to permit the letter to drop from the viewing position trap i5 to the waiting position trap I6.

The energisation of the solenoid 32 also serves to release a positive locking check applied to the spring-loaded lightweight floor bars to prevent displacement thereof against the yielding force of their holding springs by impact of a heavy letter on the floor bars. To this end, as shown in detail in Figs. 10 and l1, an adjustable link serves to couple the operating crank arm 2S, which is rotatable upon the pivotal rod 21, to a crank arm 28 which is freely rotatable upon the pivotal rod 25. The link 34 also carries adjustably ixed thereon a catch member 35 with a hooked end which is adapted to engage and hold a locking pin 35 projecting at right angles thereto from a short arm 3l' iixed to the rod 25, rThe hub of the freely rotatable crank arm 28 carries a pin 38 which projects therefrom and extends across the pin 3% so as drivingly to engage therewith in one direction of rotation of the crank arm.

The above described locking check and driving arrangement is such that when the solenoid 32 is de-energised the holding springs 3B, 3l draw the parts into the positions shown in Figs. 10 and ll so that the catch member 35 engages the locking pin 35 and positively locks the rod 25 against rotation in one direction (clockwise as viewed in Fig. 1l) thus preventing the floor bars Ell from being moved from the bottom of the trap l5, and in this position of the parts a clearance is lett between the pins 36, 38. If the solenoid E2 is now energised, the first part of the movement of the armature 33y draws up the link 34 and crank arm 28 in a lost motion movement relative to the rod 25 and crank arm 3l and thus releases the catch 35 from locking pin 36 before the latter is drivingly engaged by pin 38 which is moving with the crank arm 28. The rod 25 is then rocked by the continued upward movement of the armature 33 and link 3ft to effect the desired displacement of the iioor bars 2d. The operating crank arm 29 which is pivotally mounted upon the rod 2 is loosely coupled thereto by a coupling pin 36a rigidly fixed to and extending at right angles from an arm 37a which is keyed to the rod 2l. The pin 36a projects across the upper edge of the crank arm 2s and thus is engaged by the rising crank arm and lifted to rotate the rod 21 and displace the wire lingers 255 .from their operative position when the solenoid 32 is energised. In this case, the loose coupling is devised to prevent back drive through the wire iingers 25 which would tend to unlock the catch member 35 from the pin 36.

The loading spring 30 which returns the iioor bars to the normal trap-closing position when the solenoid 32 is de-energised is made sufriciently strong and appropriately energised to assist the return or idle movement of the armature and ensure positive re-engagement of the catch member 35 with the locking pin 36. The light wire ngers 26 are returned to the operative position shown in the drawings partly by the action of the loading spring 30 and partly by the action of the lighter and less highly tensioned loading spring 3l which acts yieldingly to maintain the wire fingers against the viewing window i2 or against the letters interposed between the window and ngers so that both light and heavy letters are smoothly brought to rest without undue strain upon the operating linkconnected to the ngers.

The waiting position trap IS is provided with a removable iioor plate 35i suspended by arms it from a pivotal rod il which is loaded by a twist spring Il?. and rocked by the armature of a solenoid d3, the arrangement and operation thereof being similar to tha-t above described with reference to the loor plate I l of the feeding trap ld.

Any or all of the movable trap-closing iioors described above may be replaced by the alternative V-flap floor arrangement shown in Figs. 14, l5 and 16. In this alternative form, the trap door comprises a pair of flaps All hinged along their outer longitudinal edges and inwardly and downwardly inclined in the transverse sense so that, when the naps are in the normal or licor closing position shown in the drawings, the inner longitudinal edges thereof meet to form a closed V-shaped channel in which the letters L rest with the bottom longitudinal edges thereof at the lowerniost point of the V, as shown in Fig. l5.

In the drawings, the V-channel floor is shown, by way of example, applied to the waiting position trap l5, with the ilaps it extending longitudinally between the side walls 5 and 5a of the trap and, in the transverse sense, extending between the rear wall il! and front panel I3.

The upper longitudinal edges of the flaps da are provided with outwardly projecting hinge pins i5 which, at one end of the trough pivotally engage in bearing slots formed in the side plate 5a (not shown), and at the other end thereof pass through a clearance opening 46 formed in the side plate 5 and pivotally engage in bearing slots formed in the back plate of a bearing bracket il which is adjustably secured to the outer lateral face of the side plate 5. The ends of the hinge pins 45 extend outwards from the bearing bracket 41 and engage therebetween a helical compression spring 48 which acts as a loading spring yieldingly to maintain the hinged flaps in the meeting or floor closing position.

The lower parts of the flaps 44 are extended so as to pass through the clearance opening d6 and project outwards from the side wall beneath the bracket Gl, and each flap extension has xed to the outer face thereof a coupling pin i9 extending parallel to the base edge of the V-channel and projecting outwards beyond the end extensions of the flaps.

The beaing bracket il mounts a solenoid 5i! set above the outwardly `projecting ends of the floor naps so that its armature 5l extends downwardly therefrom and substantially at right angles to the coupling pins lig. A cam-slotted plate provided with an inverted V-shaped groove 53 is rigidly secured in the slotte-:i lower end of the solenoid so that the plate 52 is rigidly maintained and moved in a plane at right angles to the longitudinal axes of the floor flaps coupling pins and disposed so that the opposite coupling pins enter and freely slide in the outwardly diverging limbs of the cam groove 53. The lower end oi the cam plate is connected to a helical tension spring 53a which assists the return or idle stroke of the armature when the solenoid is de-energised and also assists the return of the aps M to the floor closing position. if so desired, the solenoid, iapactuating coupling means and loading springs last described may be duplicated for application to both ends of the door flaps 4d.

llhe last described arrangement is that when the solenoid 5t is energised, the armature 5i draws the cam plate 52 upwards so as outwardly to isplace the coupling pins di? and roch the flaps fifi outwards about their upper hinged edges as the coupling pins track along the outwardly diverging limbs of the cam groove 53, thus parting the fla-ps so that any letter L resting the V -channel licor formed thereby is perniitted freely to fall therethrough and gravitate to the next trap or to further letter-handling means.

The feeding and viewing position traps lli, i5 are spaced apart by a minimum practicable distance in order that the transit time of a letter from one position to the other shall be as short as possible. The letters may be transferred solely by gravity from one trap to another, but in the apparatus shown in the drawings, driven snatch rollers Et extending through clearance openings in the rear 'wa-ll members t, it and co-operating inversely rotating follower snatch rollers 55 disposed in the gaps between the iront panels l i, i2 and if; are located. beneath the floors of the traps ii and l5 to receive each letter as it drops from the trap and positively drive the letter downwards towards the floor of the next trap. The ends of the spindles carrying the driven snatch rollers 5d carry chain sprocket wheels 55 for engagement by power actuated driving chains (not shown). The snatch rollers may be made of rubber or have rubber faced peripheral surfaces.

The waiting position trap I6 may be provided with means, e.V g. suitably positioned rotating rollers (not shown), for dressing the letter so that one end or the other of each letter is aligned in respect of a iixed abutment, in order to facilitate subsequent control of letters of various lengths.

nood

An elongated crowned guide roller 5l extends between and is mounted freely to rotate in the lower ends of the side plates 5, 5a immediately beneath the iloor of the waiting position trap IS. 'l he roller 5l, in association with a belt conveyor roller 58 journalled in bearings in the base of the framework of the letter distributor unit D, provides a receiving mouth of a flexible belt conveyor system which receives the letters released from the trap if, and `passes each letter in turn to the distributor unit D now to be more fully described.

As shown in Figs. l, 2 and 4, the belt conveyor system of the letter distributor unit comprises a plurality of flexible endless conveyor tapes disposed in laterally spaced parallel relation and for ace-to-face engagement with endless conveyor band G5 equal in width to the width ci the conveyor tape assembly. The conveyor tapes @il are passed around the receiving mouth rollers El, 5t and, together with the conveyor band are passed around a series of conveyor rollers rotating guide rods or rollers all mounted in the framework of the apparatas to rotate about horizontal axes, so that the conveyor tapes and band travel upwards in the front of the apparatus in letter-clamping relation le bottom conveyor roller 5t to the top oi w `iereupon the conveyor tapes Sd pass a direction reversing roller 65 and then trave1 downwards and past and between the cheek plates of a seri-s of six letter iverter del-Vci hereinafter more fully described. Trie lower looped ends of the endless conveyor around further rotatable guide rods and a rotatable tensioning rod El acted upon by a we J.it and are enclosed in the upper part of chute leading downwards to a collecting ``L`= for cancelled items which is mounted upon the ework base member 3.

upper looped end of the endless conveyor band is diverted from the tapes 65 to pass around a rotatable band-tensioning rod "fi acted upon by a vertically guided weight la and then passes baci: to a `point adjacent the receiving mouth or the conveyor means again to co-operatc with the conveyor tapes '64.

shown in detail in Figs. l2 and i3, each letter diverter device V iV6 comprises a pair of vertical c'neelr plates 13 secured to and projecting rearwards from the vertical frame members i in mutually spaced relation to receive therebetween the vertical stretches of the conveyor tapes E54 and a Ico-operating pair of pivotally mounted letter diverting and guiding members.

The letter guiding member of each diverter device comprises a yplurality or ngers 'M having smooth inner faces and secured at their upper ends to a horizontalv rod l@ rotatably mounted at its ends in the outer top corners of the cheek plates '.13 and closely adjacent the line of travel of the downward-ly moving conveyor tapes B so that in the normal position, as shown in the lower part of 12, the lingers 'i4 extend vertically downwards with the smooth inner faces thereof in parallel relation and contacting or in close proximity to the outer faces of the yielding fier-:ible conveyor` tapes, thus to co-operate therewith in guiding and conveying letters downwardly past the diverter devices. A suitably elongated plate with a smooth inner face may be used in place of the ngers 14.

The letter diverting member of each diverter device comprises a plurality of lingers 'E5 having smooth outer faces and' secured at their upper ends toa horizontal rod l1 rotatably mounted at its ends in the cheek plates 13 in parallel forwardly offset relation to the pivotal axis of the retaining member le so that in the normal or rest position of the diverting member (as shown in the lower part of Fig. 12) the iingers 'i5 eX- tend vertically downwards in forwardly spaced relation to the tapes 6:1. The fingers l5 are registered with the spaces between the conveyor tapes M and are narrower than the said spaces so as freely to pass therebetween when the rod Tl is rocked in anti-clockwise direction as shown at the top of Fig. l2.

The horizontal rotatable rods of the retaining member i4 and diverting member l5 are rocked by solenoid means (not shown) and may be coupled together for concerted actuation by a single solenoid or co-operating solenoids. Furthermore, the solenoid means may be coupled to the diverting and retaining means through linkages incorporating holding and locking devices to prevent uncontrolled restoration of the diverter member to the rest position by impact of a heavy letter therewith. Holding and locking means of the kind described above with reference to Figs. i0 and 11 may be adapted to serve the purpose. Alternatively a toggle linkage locking arrangement of any suitable form may be used.

The gaps between the vertically spaced cheek plates 'i3 are :fenced in by frames la with smooth vertical bars i9 the frames being removably secured to the check plates so that the bars 'i9 lie in close proximity or contact with the outer faces of the conveyor tapes 54 and guide and retain the letters in the prescribed vertically downward path of movement from one diverter device to the next. The tops of the frames 18 and upper ends of the bars i9 are rearwardly offset to lie immediately beneath the outermost position reached by the lower ends of the fully operated deecting fingers l5, as shown at the top of Fig. l2.

Brackets 8d secured to the vertical frame members l and projecting rearwards from beneath each pair of cheek plates 73 are spaced apart to support therebetween a pair of vertical fence plates Si spaced apart to form a vertical guideway or chute and having the upper parts thereof suitably shaped to provide a flared mouth disposed immediately beneath the letter discharging space between the deflected letter diverting and retaining members and leading through a restricted throat 8 ia to the chute proper, as shown at the top of Fig. 12.

C13-operating pairs of resiliently faced power driven rollers, e. g., three pairs of rubber rollers 33 as shown, are rotatably mounted upon spindles Sie, ab extending between and journalled in the bearing brackets Sil, the said spindles being disposed to either side of the guideway or chute formed by the members 8i so that the rollers through clearance openings or slots in the :tence members to meet in letter gripping engagement in the throat 85a of the chute.

As shown in the drawings, the longitudinal aires of the spindles 34, 85 are inclined to the horizontal and the line joining the centres of each eo-operating pair of rollers is also slightly inclined to the horizontal. The rollers are driven a peripheral speed which is such that the letter enga o*ed therebetween is deflected sideways in ing down the chute or guideway formed by the ice members 3i and in thus being deected sideways loses forward speed before reaching :further conveyor means, e. g., a belt conveyor or another system of conveyor tapes which passes the letter to a distributing conveyor or'letter gun. rlhis reduction in forward speed greatly reduces the liability of the letter to bounce when it reaches the aforesaid further conveyor means, and the timing of the various sizes of letters is more under control.

The diverter devices VI-Vt are electrically controlled in response to key actuation by the operator at the keyboard K and the solenoid devices for operating the above described letter traps of the letter presentation unit are likewise controlled by key actuation from the keyboard K.

Conveyor loading or letter gun track conveyors X3i-B are located beneath the delivery ends of the chutes or guideways of the diverter devices Vi-Vb to initiate the loading of the letters received from the distributor unit D on to the main conveyors C l-Ct which are placed one above the other behind the distribution unit and at different levels corresponding to the levels of the conveyors Bi-Bii and serve to convey the letters to appropriate destination containers.

In most mail sorting oiiices there is one particular selection of the many into which the letter mail is sorted which attracts a very great percentage of the mail. This selection is often that for delivery of mail to the district surrounding the sorting oiiice. It is, therefore, in such cases advisable to arrange for all items addressed to this particular destination to be separately collected together from all the sorters working on a sorting machine, especially of the type described in British Patent No. 632,403, since this mass collection of a large bulk of the mail removes a substantial demand for space on the conveying means to the remainder of the destination containers. The application of this method of sorting to the present invention is eiected by the provision of the conveyor Ci running along the top of the main sorting machine and passing horizontally at the rear of the distributor units so that letters diverted by the top diverting device Vl are loaded on to this conveyor and carried to the end of the machine where they are deposited in a local destination container or stacking box (not shown). Since only one destination container or stacking bog is fed by this conveyor the need for a control system for it such as described in British Patent No. 632.4% for the other horizontal conveyors C2-C, disappears and all the sorters have access to this conveyor all the time. This conveyor may be called the local conveyor.

ln the operation of the above described apparatus, assuming that the pneumatic letter separating device S is operating and the conveyor belt means of the distributor unit ID are being continuously driven in the direction of the arrows shown in Fig. 1, the letters L will be transferred one by one from the stack SL to the snatch rollers R and passed thereby into the open side of the trap lli to fall edgewise into the feeding position. Upon key controlled momentary energisation or" the solenoid 23, the fioor il' of trap lli will open to permit the letter to fall therethrough and become engaged between the upper snatch roller pair 54, 55. The letter will then be driven downwards between the viewing window l2 and curved wire iingers 26 so as to rest edgewise upon the ioor 2d of the trap Iii whilst held in the viewing position by the wire lingers. After viewing the letter, the operator will momentarily energise the solenoid 32 in actuating the local or coding keys according to the destination of the letter and thus open the trap :doorl 2d to permit the letter to fall therethrough and become engaged between the lower snatch roller pair Eli, 55 which drives the letter l l downwards so that it rests in the waiting position trap I6 with its bottom edge upon the trap iioor 39.

Energisation of the solenoid 43 which occurs when the local or coding keys are actuated at the keyboard K will then serve to open the trap floor 39 thereby to permit the letter to fall therethrough into the receiving mouth of the continuous conveyor belt means. The letter will thereupon become clamped between the travelling conveyor tapes G4 and conveyor band, 55:? and carried thereby up to the top of the apparatus and then diverted to travel with the conveyor tapes Si between the direction-reversing roller GS and associated guide plates 66a. Thereafter, the letters will be moved downwards with the conveyor tapes whilst pressed between the flexible tapes and rigid letter guiding and retaining members ist and guiding and retaining bars it which together form a substantially continuous and retaining wall extending from top to bottom oi the apparatus whilst the members "ed are maintained in the vertical position. Thus, the lett rs engaged between the conveyor tapes and fixed and movable guiding and retaining members may be carried down towards the bottom of the apparatus until delivered into the chute ed and discharged thereby into the cancelled items collecting box i, In certain circumstances this may happen, as hereinafter described, but normally the solenoid means provided for operating one or the other of the diverter devices Vi-VS will be energised according to prior actuation of the local or coding keys of the keyboard, whereupon the corresponding guidiirT and retaining member 'i4 will swing outwards to provide a discharge gap in the continuous guiding and retaining wall, while the fingers of the cooperating deecting member l5 will also swing outwards and pass between the conveyor tapes ell (as shown at the top of Fig. l2), thereby forming a downwardly inclined discharge passage through which the downwardly travelling letter L is deflected so as to pass into the throat S la of the discharge guideway and between the rollers 83 which are arranged to drive the letter diagonally downward so that it lands upon the corresponding conveyor Bi-Be at a reduced speed.

If the diverter device Vi is operated, the deflected letter will be discharged onto the loading track conveyor Bi and passed therealong to the local conveyor Ci for conveyance to the common collecting box for all letters diverted to the local conveyor.

On the other hand, if any one of the other diverter devices Vif- V5 is operated, the letter will be discharged on to the corresponding letter gun track. conveyor BZ--B and conveyed thereby to a letter gun device G (Fig. 3) which will operate under control as described in the prior British patent specication No. 632,403 to place the letter in an appropriate position upon the corresponding conveyor CZ-CG which will convey the letter to the appropriate destination container. Each of the conveyors CZ-Cii may have associated therewith a plurality oi destination containers and a diverting device associated with each destination container and automatically operated selectively to divert letters from the conveyor into the appropriate container.

The keyboard K may also be provided with a cancelling key which the operator can use to cancel the keying or coding for any letter still in the waiting position and which the operator may realise he has mis-keyed. The cancelling key will serve to prevent energisation of the solenoids which operate the diverter devices Vl--Vt` and such cancelled items will then be passed straight through to the cancelled item box 'it located near the operator as above described.

The method of conning the'viewing oi" the letters and reading of the addresses thereon to the normal viewing position i. e., when the letters are in the trap I 5, as described above, may be regarded as the elementary method of utilising the apparatus of this invention. When the operator has become suiiiciently experienced in the manlaulation of the apparatus, he may be able also to make use of a transparent viewing window provided in the front of the feeding trap I4. With such an arrangement, the operator can transfer his attention, at will, from the letter held in the normal viewing position trap I5 to the following letter held in the feeding trap I4 and thus overlap the function of reading the address of one letter with the act of keying the destina-tion code according to the memorised address of the preceding letter and causing the trap release of the two or three letters involved in the overlapping functions.

It will be appreciated that the devices ior eiieoting the various movements involved in the distribution of the letters'may take any convenient form and for example, although reference has been made to electro-magnetic devices for actuating the release devices associated with the letter traps, mechanically or pneumatically operating devices may be employed.

We claim:

l. in apparatus for distributing articles such as postal letters, postcards, packets and the like, in accordance with their destination addresses or other characteristics, at least letterpresentation unit comprisingr a downwardly extending chute, displaceable floor members extending across said chute transversely to divide said chute into upper, middle and lower sections constituting a feeding position trap, a viewing position trap and a waiting position trap respectively, said feeding position trap having an opening therein through which said letters are fed one at a time so as to rest on edge on said displaceable floor of said feeding position trap, said viewing position trap having a lateral opening forming a viewing window, said traps being set one above another so that each letter in turn is segregated in said feeding position trap, 'then dropped therefrom so as to rest on edge upon said iioor oi said viewing position trap, with the addressed face of lsaid letter displayed through said viewing window opening, and thereafter dropped from said viewing position trap into waiting position trap, devices for determining the dis'- placement of said trap floor members to release each said letter in turn from each said trap in turn, and manually operated coding keys to control the operation of said devices.

2. rihe apparatus claimed in claim l, wherein said feeding position trap and wai position trap each have front and rear walls disposed vertically to denne vertical passageway-s tween, and said viewing position trap iront and rear walls forwardly inclined in the downward direction to define an inclined passageway therebetween, and said viewing window opening is formed in said inclined front wall of said viewing position trap.

3. The apparatus claimed in claim 1, wherein said feeding position trap is provided with a lateral opening forming a preliminary viewing window set immediately above said viewing window opening in said viewing position trap.

4. Apparatus as claimed in claim l, wherein said feeding position trap is provided with a lateral opening forming a viewing window, and including transparent panels covering said lateral viewing window openings of said feeding position trap and said viewing position trap and forming transparent viewing windows.

5. The apparatus as claimed in claim l, wherein said feeding position trap is provided with a lateral opening through which to introduce letters one at a time into the said trap, and guide means arranged to guide the letters edge first through said lateral opening and into said trap so as to rest on edge upon the said iloor of said trap.

6. The apparatus as claimed in claim 1, wherein said feeding position trap is provided with a lateral opening through which to introduce letters into the said feeding position trap, guide means arranged to guide the letters edge rst through said lateral opening and into said feeding position trap, so as to rest on edge upon said floor of said trap, and stop means associated with the lower edge of said lateral opening and arranged to engage the rear edge of each said letter deposited upon the said floor or" said feeding position trap and so prevent a letter from bouncing back if forcibly fed into said feeding position trap.

7. The apparatus as claimed in claim l, wherein at least one of said releasahle trap door inembers comprises a series of pivotally mounted bars arranged to extend across the said chute to form support for a letter resting edgewise thereon, and means for swinging said pivotally mounted door bars out of said letter-supporting position to permit the letter supported thereby to fall from said trap with which said door member associated, and means for returning said pivotally mounted iioor bars to the letter-supporting position,

8. The apparatus as claimed in claim l, wherein at least one of said releasable trap floor roemhers comprises at least one pivotally mounted plate arranged to project transversely of said chute to form a support for a letter resting edgewise thereon, and means for swinging said pivotally mounted door plate out of said letter-supf' porting position to permit the letter supported thereby to fall from said trap with which said door plate is associated, and means for returning pivotally mounted iioor plate to the letter-supporting position.

The apparatus clairne in l, wherein at least one of said releasable trap door ineinbers comprises a series of pivotally mounted bars arranged to extend across the said chute to form a support for a letter resting edgewise thereon, .intro-magnetic means for positively swinging id pivotal floor bars out of said letter-supportng position to permit the said letter supported hereby to fall from the said trap with which said floor bars are associated, when said electro-inagnetic means are energised, and spring means for yieldinffly holding said pivotally mounted floor hars in the said letter-supporting position and returning said bars to said letter-supporting position after the deflection of hars to release said letter.

lo. The apparatus as claimed in claim l, wherein at least one of said relea-sable trap floor members comprises at least oneY pivotalli7 mounted plate arranged to project across the Il d said chute to form a support for a letter resting edgewise thereon, electro-magnetic means for positively swinging said pivotal iioor plate out of said letter-supporting position to permit the said letter supported thereby to fall from the said trap with which said floor plate is associated, when said electro-magnetic means are energised, and spring means for yieldingly holding said pivotally mounted floor plate in the said letter-supporting position and returning said licor plate to said letter-supporting position after the deiiection of said oor plate to release the said letter.

l1. The apparatus as claimed in claim l, including spring-loaded lightweight fingers pivotally mounted so as to engage and control the position of each letter which falls into the viewing position trap.

l2. The apparatus as claimed in claim l, including spring-loaded lightweight fingers pivotally mounted so as to engage and control the position of each letter which falls into said viewing position trap, and means for linking said pivotally mounted lingers to said displaceable licor member of said viewing position trap for concerted actuation of said ngers and said trap oor member by said means for displacing said trap floor member.

13. ,The apparatus as claimed in claim l, wherein at least one of said releasable trap oor members comprises a series of pivotally mounted bars arranged to extend across the said chute to form a support for a letter resting edgewise thereon, and electromagnetic means for swinging said pivotally mounted iloor bars out of said letter-supporting position to permit the letter supported thereby to fall from said trap with which said door member is associated, means for returning said pivotally mounted floor bars to said letter-supporting position, locking means for positively locking said trap floor hars in said letter-supporting position, thereby to prevent trap floor bars from being deflected from said letter-supporting position by the impact f a heavy letter thereon, and means for linking said locking means to said electro-magnetic devices for determining the displacement or said trap door bars, so that said electro-magnetic devices act to release said locking means from said trap floor bars prior to displacing said trap floor members from the letter-supporting position,

i4. The apparatus as claimed in cla l, wherein the said trap door member of at least one of said letter-presentation traps comprise a pair of flap plates which are substantially horizontal longitudinally and disposed side by side and inwardly and downwardly inclined towards each other in the transverse sense to iorrn a closed V-channel door, said iiap plates being hinged to pivot about their top edges so that the inwardly inclined plates can be swung downwards and away from each other to permit a letter supported thereon to fall therebetween and pass downwards from said trap with which said nap plates are-associated.

15. The apparatus claimed in claim l, wherein the said trap floor member ci at least one of said letter presentation traps comprise a pair of flap plates which are substantially horizontal longitudinally and disposed side by side and inwardly and downwardly inclined towards each other in the transverse sense to forni closed V-channel floor, said flap plates being hinged to pivot'about their top edges so that the inwardly inclined plates can be swung downwards and away from each other to permit a letter supported thereon to fall therebetween and pass downwards from said trap with which said lap plates are associated, rigid coupling members projecting from the opposite ends of each said flap plate, cam means engaged by said rigid coupling members, and an electro-magnetic actuating device drivingly connected to said cam means so that said fla-p plates are swung downwards about their hinge axes when said electromagnetic actuating device is energised.

i6. The apparatus claimed in claim l, wherein said trap door member of at least one oi said letter-presentation traps comprise a pair or flap pla-tes which are substantially horizontal longitudinally and disposed side by side and inwardly and 4downwardly inclined towards each other .in the transverse sense to form a closed V-channel door, said flap plates being hinged to pivot about theii` top edges so that the inwardly inclined plates can be swung downwards and away from each other to permit a letter supported thereon to fall between said vparted plates and downwards from said trap with which said flap plates are associated, and loading spring means which yieldingly hold said ap plates in the V-channel Forming position.

17, In apparatus for distributing articles such as postal letters, postcards, packets and the like, in accordance with their destination addresses or other characteristics, at least one letterpresentation unit -comprising a downwar .ly ei;- tending chute, displaceable hoor members extending across said chute transversely to divide said chute into upper, middle and lower sections constituting a feeding position trap, a viewing position trap and a waiting position trap respectively, said feeding position trap having an opening therein through which said letters are fed one by one so as to rest on edge on said displaceable floor of said feeding position trap, said viewing position trap having a lateral opening forining a viewing window, said traps being set one above another so that each said letter in turn is segregated in said feeding position trap, then dropped therefrom so as to rest upon edge upon said door of said viewing position trap, with the addressed face of said letter displayed through said viewing position window opening, and thereafter dropped from said viewing position trap into said waiting position trap, means for determining the displacement of said trap floor members to release each said letter in turn from each said trap in turn, and manually operated coding keys to control the operation of said means, and a letter-distributor unit embodying means for selectively diverting a succession of letters to diierent paths of travel, and means for transferring each letter released from said waiting position trap of said letter-presentation unit to said letter-distributor unit.

1S. The apparatus claimed in claim 17, includco-operating roller means disposed between the lower end of said feeding position trap and upper end of said viewing position trap, and further co-operating roller means disposed between the lower end `of said viewing position trap and upper end of said waiting position trap to provide means for assisting the downward passage of the letters from trap to trap, and means for positively driving said co-operating roller means.

19. The apparatus as claimed in claim 17, cluding spring-loaded .lightweight lingers pivotally mounted so as to engage and control the position of each .letter which falls into the viewing position trap, and means for linking said pivotally mounted iingers to said displaceable floor member of said viewing position trap for concerted actuation of both said lingers said trap floor member by said means employed for msplacing said trap floor member.

2G. The apparatus claimed in claim 17,. wherein the said trap floor member of at least one of said letter-presentation traps comprise a pair of iiap plates which are substantially horizontal longitudinally anddisposed side by vside and inwardly and downwardly inclined towards each other in the transverse sense to form a closed `t'channel door, said nap plates being hinged to pivot about their top edges so that the inwardly inclined plates can be swung downwards and awa-y from each other to permit a letter supported thereon to fall between parted plates and pass downwards i'rom said trap with which said nap plates are associated, rigid coupling members projecting from the opposite ends of said nap plates, cam means engaged by said rigid coupling members, an electro-magnetic actuating device drivingly connected to said cam means so that said flap plates are swung downwards about their hinge axes when said electro-magnetic actuating devic-e is energised, and loading spring means which i ingly hold said iiap plates in the V-channel ,iorining position.

21, In apparatus for distributing articles such postal letters, postcards, packets and the like, in accordance with their destination addresses or other characteristics, the combination of at least letter-presentation unit comprising a downwardly extending chute, displaceable door memb extending across said chute transversely to divide said chute into upper, middle and lower sections constituting a feeding position trap, a viewing position trap and a waiting position trap respectively, said feeding positie. trap having an opening therein through which said letters a `e fed one at a time so as to rest on edge on said displaceable floor of said feeding position trap,

viewing position trap having a lateral openforming a viewing window, said traps being set one above another so that each said letter in turn is segregated in said feeding position trap, then dropped therefrom so as to rest on edge upon said floor of said viewing trap, with the addressed face of said letter displayed through said viewing position window opening, and thereafter dropped from said viewing position trap into said waiting position trap, devices for determining the displacement of said trap floor members to release each said letter in turn from each said trap in turn, and manually operated coding keys to control the operation of said devices, a plurality of substantially horiaontal conveyors disposed at diierent levels, a letter distributor unit embodyingv a downwardly extending passageway, a plurality of diverter devices located adjacent said passageway for selectively diverting a succession of letters to said horizontal conveyors, and further letter conveyor means for raising each letter from the level which it is released from said waiting position trap to a level above that of the highest one of said horizontal conveyors and thereafter passing said raised letters downwards through said downwardly extending passageway and past said di` verter devices so that each letter is diverted by a diverter device towards a selected one of horizontal conveyors.

22. The apparatus claimed in claim 2l, wherein ,I y faid cons fiori -ialsmegch siii@ lett ...fiom which said letter is released from said waiting positionparries `said, letters tdthe top u fnfria,ssageway sgwthat Lsaid letters subsequently travel ne by one down said dil.' 4 verter passageway for engagement with a Vselectedioiie bsaiddiverter devices. n e,

23. The apparatusmas, claimed in claim 2l, fr raising each Sara leiter from the ie dat which ityisjiilsed frm said waiting position trap comprise a travelling conveyor belt system including a plurality oi exible conveyor tapes disposed in spaced parallel relation, and means for guiding said conveyor tapes to ferm an inner moving wall of the said downwardi; extending passageway along which said letters are conveyed from one to another of said diverter devices.

24. The apparatus claimed in claim 2l, wherein said letter diverter devices each comprise a letter diverter member forming part of an inner wall of said diverter passageway, and a letter guiding and retaining member forming a part of an outer wall of said diverter passageway, each said letter diverter member being pivotally mounted so as to swing across the said diverter passageway into the path of the letters passing down said passageway, each of said letter guiding and retaining members being pivotally mounted so as to swing outwards to provide a discharge opening for the passage of the letters diverted from said passageway by said outwardly swung associated diverter member, and means for swinging said members about their respective pivots to the letter diverting and retaining and guiding positions respectively.

25. The apparatus claimed in claim 21, wherein said conveyor means for raising the said letters from the level at which they are released from said waiting position trap include spaced parallel conveyor tapes and means for guiding a stretch of each said conveyor tape downwards to form the inner wall of said downwardly extending diverter passageway, and wherein said letter diverter devices each comprise a letter dverter formed by a plurality of fingers disposed in alignment with the spaces between the downwardly travelling stretches of said conveyor tapes forming the said inner wall of the said diverter passageway, and associated letter guiding and retaining means consisting of a plurality oi' nngers arranged to form part of an outer wall of said diverter passageway, said letter diverter devices and letter guiding and retaining means being pivotally mounted, and means for swinging each said diverter device and each said guiding and retaining device about its pivotal axis tc the letter diverting and retaining and guiding positions respectively.

26, The apparatus claimed in claim 2l, wherein said letter diverter devices each comprise a letter' diverter member forming part of an inner wall of said diverter passageway, and a letter guiding and retaining member forming a part of an outer wall of said diverter passageway, each said letter diverter member being pivotally mounted so as to swing across the diverter passageway into the path of the letters passing down said passageway, each of said letter guiding and retaining members being pivotally mounted so as to swine" outwards to provide a discharge open- 1i-iight. .im ed therewith, and cooperating roller means disposed to receive the letters diverted from said passageway by said diverter devices and feed said diverted letters into the upper ends of the respective chutes, said (zo-operating roller means being disposed to change the direction of travel of the letters received thereby so that the velocity of the letters is reduced as they are passed through said chutes and discharged from the lower ends thereof.

28. The apparatus claimed in claim 21, including a plurality of containers identified with the destinations of the letters released from said waiting position trap of said letter-presentation unit and individually identified with the horizontal conveyors so that the letters selectively diverted to said horizontal conveyors are deposited thereby in the appropriate destination boxes.

29. The apparatus claimed in claim 28, wherein said conveyor means for raising the letters from the level at which they are released from said waiting position trap include spaced parallel conveyor tapes and means for guiding a stretch of each said conveyor tape downwards to form the inner wall of the said downwardly extending diverter passageway, and wherein said letter diverter devices each comprise a letter diverter formed by a plurality of fingers disposed in alignment with spaces between the downwardly travelling stretches of said conveyor tapes forming the said inner wall of said diverter passageway, and associated letter guiding and retaining means consisting of a plate arranged to form part of an outer wall of said diverter passageway and pivoted to swing about its upper edge, said letter diverter members each being pivoted to swing across the said diverter passageway into the path of the letters passing down said passageway, each of said letter guiding and retaining means being arranged to swing outwards about its pivot to provide an opening in the said outer wall or said passageway for the passage of letters diverted from said passageway by said transversely swung associated diverter member, and means for swinging said diverter members and retaining and guiding means about their respective pivots to the letter diverting and guiding and retaining positions respectively.

3i). The apparatus claimed in claim 28, Wherein said ietter diverter devices each comprise a letter diverter member forming part of an inner wall of said diverter passageway, and a letter guiding and retaining member forming a part oi an outer wall of said diverter passageway, each said letter` diverter member being pivotally mounted so as to swing across the diverter passageway into the path of the letters passing down said passageway, each of said letter guiding and retaining members being pivotally mounted so 19 as to swing outwards to provide a discharge opening for the passage of the letters diverted from said passageway by said transversely swung associated diverter member, an electro-magnetic actuating means drivingly coupled to said letter guiding and retaining member and said letter diverter member associated therewith so that said electro-magnetic actuating means, when energised, displaces said members to the respective letter diverting positions, loading spring means for returning said members to their respective letter guiding and retaining positions, locking means for positively holding each said letter diverting member in the letter diverting position across said diverter passagewamand thereby preventing the deection of said diverter 20 member by the impact of a heavy letter, Vand means whereby said letter diverter member is released from said locking means when said electro-magnetic means are actuated for moving said letter diverter member into the letter diverting position across said passageway.

References Cited in the 111e of this patent K UNITED STATES PATENTS Great Britain Nov. 2a, 1949 

